/*
 * Copyright (C) 2011 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.android.volley.toolbox;

import android.os.Handler;
import android.os.Looper;

import com.android.volley.Cache;
import com.android.volley.NetworkResponse;
import com.android.volley.Request;
import com.android.volley.Response;

/**
 * A synthetic request used for clearing the cache.
 */
public class ClearCacheRequest extends Request< Object >
{
	private final Cache mCache;
	private final Runnable mCallback;
	
	/**
	 * Creates a synthetic request for clearing the cache.
	 * @param cache Cache to clear
	 * @param callback Callback to make on the main thread once the cache is clear,
	 * or null for none
	 */
	public ClearCacheRequest(
			Cache cache,
			Runnable callback )
	{
		super( Method.GET, null, null );
		mCache = cache;
		mCallback = callback;
	}
	
	@Override
	public boolean isCanceled()
	{
		// This is a little bit of a hack, but hey, why not.
		mCache.clear();
		if( mCallback != null )
		{
			Handler handler = new Handler( Looper.getMainLooper() );
			handler.postAtFrontOfQueue( mCallback );
		}
		return true;
	}
	
	@Override
	public Priority getPriority()
	{
		return Priority.IMMEDIATE;
	}
	
	@Override
	protected Response< Object > parseNetworkResponse( NetworkResponse response )
	{
		return null;
	}
	
	@Override
	protected void deliverResponse( Object response )
	{
	}
}
